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Cardiac Pacemaker (cardiac + pacemaker)
Selected AbstractsPersistence of Left Supracardinal Vein in an Adult Patient with Heart,Hand Syndrome and Cardiac PacemakerCONGENITAL HEART DISEASE, Issue 3 2008Jan Nemec MD ABSTRACT A patient with a sporadic heart,hand syndrome, which includes thumb hypoplasia, septum primum atrial septal defect, and cleft mitral valve is described. During attempted placement of a pacemaker lead, persistence of left superior and inferior vena cava was found in addition to the right-sided caval veins. This corresponds to persistence of left-sided supracardinal vein present during fetal development. [source] Emergency Reprogramming of Cardiac Pacemakers: Part IIPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2000BERNARD H. BOAL No abstract is available for this article. [source] A Petri Net Approach to Remote Diagnosis for Failures of Cardiac PacemakersQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 8 2004S. K. Yang Abstract This paper describes the application of Petri nets to remote diagnosis for failures of cardiac pacemakers. The operations, structures and basic control methods of the different types of cardiac pacemakers are first described. A combined synchronous pacemaker is modeled into a Petri net in this study. Twelve checkpoints are added into the modeled Petri net so as to construct a Petri net for failure diagnosis. A remote mode for failure diagnosis of implanted pacemakers is also designed by the Petri net approach. A low-power transmitter transmits a checking-code with 12 digits from the implanted pacemaker to the outside of the patient's body manually or automatically. By observing the markings of the checking code, the working status and the health condition of the pacemaker are clear at a glance. Applications of the Petri net method for failure diagnosis and control optimization are discussed. Copyright © 2004 John Wiley & Sons, Ltd. [source] Unexpected Loss of Bipolar Pacing With Implanted Dual Chamber PacemakersPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 1 2000G. BIH-FANG GUO Bipolar leads are most commonly used in the current practice of pacemaker therapy. In our study of 124 patients implanted with Guidant/Cardiac Pacemakers (CPI) Vigor dual chamber pacemakers, 5 patients had unexpectedly abrupt increases in bipolar lead impedance and pacing threshold 2 weeks to 18 months postimplantation without changes in sensing function. With the lead configuration reprogrammed to unipolar, the lead impedance and pacing threshold were restored to appropriate ranges. The changes in bipolar lead parameters can be caused by the CPI's "Quick Connect" (QC1) header lead system incorporated in these pacemakers. [source] Role of the neuropeptide CCAP in Drosophila cardiac functionDEVELOPMENTAL NEUROBIOLOGY, Issue 3 2005Davide Dulcis Abstract The heartbeat of adult Drosophila melanogaster displays two cardiac phases, the anterograde and retrograde beat, which occur in cyclic alternation. Previous work demonstrated that the abdominal heart becomes segmentally innervated during metamorphosis by peripheral neurons that express crustacean cardioactive peptide (CCAP). CCAP has a cardioacceleratory effect when it is applied in vitro. The role of CCAP in adult cardiac function was studied in intact adult flies using targeted cell ablation and RNA interference (RNAi). Optical detection of heart activity showed that targeted ablation of CCAP neurons selectively altered the anterograde beat, without apparently altering the cyclic cardiac reversal. Normal development of the abdominal heart and of the remainder of cardiac innervation in flies lacking CCAP neurons was confirmed by immunocytochemistry. Thus, in addition to its important role in ecdysis behavior (the behavior used by insects to shed the remains of the old cuticle at the end of the molt), CCAP may control the level of activity of the anterograde cardiac pacemaker in the adult fly. Expression of double stranded CCAP RNA in the CCAP neurons (targeted CCAP RNAi) caused a significant reduction in CCAP expression. However, this reduction was not sufficient to compromise CCAP's function in ecdysis behavior and heartbeat regulation. © 2005 Wiley Periodicals, Inc. J Neurobiol, 2005 [source] The Early History of Cardiac Surgery in StockholmJOURNAL OF CARDIAC SURGERY, Issue 6 2003Kjell Radegran M.D. The portal figure is Clarence Crafoord (1899,1983) who already in 1927 had succeeded with the Trendelenburg pulmonary embolectomy operation. He went on to develop lung surgery in general. With foresight he stimulated the chemists of Karolinska Institute to purify heparin, first for prophylaxis against venous thromboembolism and later for use with the heart-lung machine. In 1944 he became the first surgeon to successfully operate on patients with coarctation of the aorta. With Viking Olov Bjork and Ake Senning the heart-lung machine was improved, finally allowing its clinical use in a patient operated in 1954 for a myxoma of the left atrium, with long-term survival. This was the first successful use of the heart-lung machine in Sweden and the second in the world. He and his coworkers, first at the Sabbatsberg hospital and from 1957 at the Karolinska hospital made major contributions to cardiology and radiology, apart from the progresses in cardiac surgery. Contributions such as pressure recording from the left atrium by needle puncture in 1950, the Senning operation for transposition of the great arteries and the first use of a totally implantable cardiac pacemaker in 1958 are indeed medical history. (J Card Surg 2003;18:564-572) [source] Ageing to arrhythmias: conundrums of connections in the ageing heartJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 12 2006Sandra A. Jones The proportion of the population that is elderly continues to increase, leading to an increasing need to address problems chiefly associated with old age. Progressive ageing of the heart is associated with an increasing incidence of arrhythmias and disorders of the normal origin of the heartbeat, the sinoatrial node. This intrinsic pacemaker of the heart has an increasing tendency with age to lose its dominant role in pacing the heart, and regulation of heart rate becomes erratic. This ,sick sinus syndrome' is associated with fainting, palpitations, shortness of breath and sudden death. Current treatment of this condition is by implantation of an artificial pacemaker, an intervention increasingly required with age. The current evidence suggests that the normal heartbeat fails due to changes in the expression of critical proteins that ensure the correct production and conduction of the cardiac action potential. Depletion of a protein directly responsible for providing electrical connections between the cells of the heart, connexin 43, appears to leave the normal cardiac pacemaker disconnected and unable to drive the heart. This process may be associated with age-dependent changes in stress-related signalling. Simple interventions such as exercise could impact on the processes hypothesized to be involved and may offer a means to preserve the stability of the electrical activity of the heart into old age without pharmacological manipulation. [source] Estimation of Left Ventricular Filling Pressure by Doppler Echocardiography in Dogs with Pacing-Induced Heart FailureJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 3 2008K.E. Schober Background: Congestive heart failure (CHF) is a common clinical syndrome characterized by elevated filling pressure. Hypothesis: Doppler echocardiographic (DE) variables of left ventricular (LV) filling can predict a decline of LV end-diastolic pressure (LVEDP) induced by acute preload reduction in dogs with compensated CHF. Animals: Five male hound dogs. Methods: Dogs previously instrumented with a transvenous cardiac pacemaker and a LV pressure gauge were paced at 160,180 bpm to induce mild CHF characterized by LVEDP > 20 mmHg. LVEDP and 9 DE variables of LV filling derived from diastolic time intervals, transmitral and pulmonary venous flow, and tissue Doppler imaging were measured simultaneously at baseline and 30, 60, 120, and 240 minutes after furosemide (4 mg/kg, IV) or placebo (0.9% saline, IV). Repeated measures analysis of variance and correlation analysis were used to determine the association between the decline of LVEDP after furosemide and DE measures of LV filling pressure (LVFP). Results: Furosemide but not placebo decreased LVEDP (P < .001). The ratio of early transmitral flow velocity to LV isovolumic relaxation time (E : IVRT) predicted LVEDP best (R2= .50; P < .001). Correlations were also found between LVEDP and IVRT, E, ratio between E and late diastolic transmitral flow velocity (E : A), and early diastolic velocity of the mitral annulus (Ea). The ratio of E to Ea (E : Ea) was not useful in the prediction of LVEDP in this model. Conclusion and Clinical Importance: E : IVRT can be used to predict LVFP in dogs with mild left-sided CHF induced by rapid pacing. [source] Pacemaker Reed Switch Behavior in 0.5, 1.5, and 3.0 Tesla Magnetic Resonance Imaging Units: Are Reed Switches Always Closed in Strong Magnetic Fields?PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 10 2002ROGER LUECHINGER LUECHINGER, R., et al.: Pacemaker Reed Switch Behavior in 0.5, 1.5, and 3.0 Tesla Magnetic Resonance Imaging Units: Are Reed Switches Always Closed in Strong Magnetic Fields? MRI is established as an important diagnostic tool in medicine. However, the presence of a cardiac pacemaker is usually regarded as a contraindication for MRI due to safety reasons. The aim of this study was to investigate the state of a pacemaker reed switch in different orientations and positions in the main magnetic field of 0.5-, 1.5-, and 3.0-T MRI scanners. Reed switches used in current pacemakers and ICDs were tested in 0.5-, 1.5-, and 3.0-T MRI scanners. The closure of isolated reed switches was evaluated for different orientations and positions relative to the main magnetic field. The field strengths to close and open the reed switch and the orientation dependency of the closed state inside the main magnetic field were investigated. The measurements were repeated using two intact pacemakers to evaluate the potential influence of the other magnetic components, like the battery. If the reed switches were oriented parallel to the magnetic fields, they closed at 1.0 ± 0.2 mT and opened at 0.7 ± 0.2 mT. Two different reed switch behaviors were observed at different magnetic field strengths. In low magnetic fields (< 50 mT), the reed switches were closed. However, in high magnetic fields (> 200 mT), the reed switches opened in 50% of all tested orientations. No difference between the three scanners could be demonstrated. The reed switches showed the same behavior whether they were isolated or an integral part of the pacemakers. The reed switch in a pacemaker or an ICD does not necessarily remain closed in strong magnetic fields at 0.5, 1.5, or 3.0 T and the state of the reed switch may not be predictable with certainty in clinical situations. [source] Pressure cutaneous ulcer over a pacemaker successfully treated with left subcostal transplantation in an extremely thin patientTHE JOURNAL OF DERMATOLOGY, Issue 8 2006Manabu HAMADA ABSTRACT Implantation of a permanent cardiac pacemaker is becoming common with the increase in the elderly population. A cutaneous ulcer over the pacemaker is a rare complication. Most such cases previously reported demonstrate non-specific granuloma histologically, negative patch testing of materials used in the device, and no growth in the bacterial culture taken from the generator pocket. To date, the conventional treatments often result in a disap-pointing outcome. We describe an extremely thin 79-year-old Japanese male with a pressure cutaneous ulcer caused by the presence of a pacemaker device. This patient was referred to us with a 1-month history of repeated cutaneous ulcer and exposure of the cardiac pacemaker in the left pectoral area. Conservative treatment was not effective. Treatment with left subcostal implantation of a new pacemaker, which was not wrapped, and disposition of the electrodes in the subcutaneous tissue of the thorax was successful. Cutaneous manifestations have not recurred for 5 years. Considering the poor condition of the patient, subcostal translocation of the pacemaker was a simple and acceptable treatment for pressure cutaneous ulcer over the pacemaker. [source] Application of a vagal nerve stimulator in an epilepsy patient with cardiac pacemaker after post-ictal cardiac arrestACTA NEUROLOGICA SCANDINAVICA, Issue 2 2009R. Cáceres In this case report we present a patient with temporal lobe epilepsy (TLE) showing partial complex seizures and secondary generalization, and treated with several antiepileptic drugs. After two consecutive seizures she had an episode of cardiac arrest followed by AV-block III which led to the implantation of a cardiac pacemaker. She subsequently received a vagal nerve stimulator because of poor response to epilepsy treatment. Combined treatment with two different electromagnetic stimulators raises the question of safety during surgery which is discussed. [source] Clinical characteristics and outcomes for a modern series of primary gliosarcoma patientsCANCER, Issue 5 2010Seunggu J. Han BS Abstract BACKGROUND: Primary gliosarcoma (PGS) is a rare central nervous system tumor with limited experience reported in the literature. In the current study, the authors present a modern series of confirmed PGS cases treated in the era of magnetic resonance imaging (MRI), after the accepted glioblastoma management of resection, radiation, and temozolomide. METHODS: Using a retrospective review, patients with confirmed PGS were identified (1996-2008). Cases were determined to be PGS by central pathology review using the 2007 World Health Organization criteria. Extensive chart review was performed to gather clinical and pathologic data on these cases. RESULTS: All but 1 patient had undergone a preoperative MRI, with 1 patient receiving a computed tomography scan due to a cardiac pacemaker. A total of 10 patients received radiotherapy with concurrent and adjuvant temozolomide chemotherapy, and 8 patients received radiotherapy alone or in combination with other chemotherapeutic agents. In 2 patients, the history of adjuvant treatment could not be confirmed. The overall median survival was 13.9 months (range, 2.2-22.9 months). Patients with gliosarcomas resembling meningioma were found to have a significantly prolonged median survival compared with patients harboring gliosarcoma resembling glioblastoma multiforme (16 months vs 9.6 months; P = .011). However, no difference in survival was noted between patients who received concurrent radiotherapy and temozolomide compared with those who did not (10.4 months vs 13.9 months; P = .946). CONCLUSIONS: The results of the current study support previous hypotheses that there are 2 distinct types of PGS. The type mimicking the appearance of a meningioma appears to carry a significantly more favorable prognosis, most likely due to an increased chance at achieving macroscopic total resection. Cancer 2010. © 2010 American Cancer Society. [source] Integrated medical feedback systems for drug delivery,AICHE JOURNAL, Issue 4 2005Adam Heller Drugs are now administered at frequencies and doses based on averages optimized for large populations. Because the optimal frequency and dose for an individual differs, transiently or permanently, from that of a population's average, the dosing is necessarily suboptimal. Feedback loop-based individualized integrated medical systems, comprising an implanted sensor, battery, amplifier, processor, and actuator are now in use in cardiac pacemakers and defibrillators. Drug-delivering medical feedback loops, comprising miniature sensors and drug pumps, would individualize, and thereby improve the effectiveness and safety of drugs. Their sensor would continuously or frequently monitor the effect of the drug and adjust, through a medical control algorithm, its flow to the minimum necessary for effectiveness, reducing thereby side effects and improving the success rate of experimental drugs. The pace of integration of the drug delivering feedback loops depends on the availability of proven miniature components and of medical control algorithms. © 2005 American Institute of Chemical Engineers AIChE J, 2005 [source] A Petri Net Approach to Remote Diagnosis for Failures of Cardiac PacemakersQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 8 2004S. K. Yang Abstract This paper describes the application of Petri nets to remote diagnosis for failures of cardiac pacemakers. The operations, structures and basic control methods of the different types of cardiac pacemakers are first described. A combined synchronous pacemaker is modeled into a Petri net in this study. Twelve checkpoints are added into the modeled Petri net so as to construct a Petri net for failure diagnosis. A remote mode for failure diagnosis of implanted pacemakers is also designed by the Petri net approach. A low-power transmitter transmits a checking-code with 12 digits from the implanted pacemaker to the outside of the patient's body manually or automatically. By observing the markings of the checking code, the working status and the health condition of the pacemaker are clear at a glance. Applications of the Petri net method for failure diagnosis and control optimization are discussed. Copyright © 2004 John Wiley & Sons, Ltd. [source] | ||||||||||